In power semiconductor devices, for example IGFETs (insulated gate field effect transistors) a load current typically flows in a vertical direction between two load electrodes formed at opposite sides of a semiconductor die. In a blocking mode field plate structures extending from one side into the semiconductor die deplete a drift portion of the semiconductor die and facilitate higher dopant concentrations in the drift portion without adverse impact on the blocking capability. Shrinking the field plate structures to needle-shaped field plate structures facilitates a grid-like gate structure between the field plate structures, wherein the grid-like gate structure provides a larger total channel width per unit area than comparable stripe-shaped gate structures.
It is desirable to improve reliable semiconductor devices with needle-shaped field electrodes and low parasitic capacitances.